Improve Google Lighthouse Scores

[kumar-ish]

As in title. The scores are pretty good (I think), but a bunch of them are easy to get fixed nonetheless.

Screenshot from one of the pages:

[MaxwellBo]

meanwhile the homepage

[MaxwellBo]

The homepage has improved now that a bunch of images have been removed. I think the rest of the work are some quick wins for some easy SEO.